/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/Collision/ParticlePairMidPhase.h
Destroy all collisions and prevent this midphasae from being used any more. Called when one of its particles is destoyed. It will be culled at the next Prune in the CollisionConstraintAllocator. We don't delete it immediately so that we don't have to remove it from either Particle's ParticleCollisions array (which is O(N) and unnecessary when the particles are being destroyed)
void DetachParticle ( [FGeometryParticleHandle](API\Runtime\Chaos\Chaos\FGeometryParticleHandle) * Particle )